Dur-Zong Hsu

Sesamol delays mortality and attenuates hepatic injury after cecal ligation and puncture in rats: role of oxidative stress.

ABSTRACT Sesame oil potently protects rats against sepsis, and sesamol appears to be the protective ingredient in sesame oil. The aims of the present study were to examine the effects of sesamol on mortality and reactive oxygen species-associated liver injury in Wistar rats with cecal-ligation-and-puncture-induced sepsis (septic rats). After sepsis was induced, sesamol was administered every 6 h. The survival rate was determined during the ensuing 48 h. Hepatic injury was assessed using blood biochemistry and histological examination. Hepatic oxidative stress was assessed by determining the levels of liver lipid peroxidation, hydroxyl radical, and superoxide anion generation, and nitric oxide production 12 h after cecal ligation and puncture. Inducible nitric oxide synthase expression was also determined. Sesamol delayed mortality and attenuated hepatic injury in septic rats. Hepatic lipid peroxidation, hydroxyl radical, and superoxide anion levels were significantly lower in sesamol-treated septic rats. Furthermore, sesamol inhibited the production of nitrite and the expression of inducible nitric oxide synthase in the liver in septic rats. Therefore, sesamol may delay mortality and attenuate oxidative stress-associated liver injury by inhibiting the production of nitric oxide, at least partially, in septic rats.

Effect of sesame oil on oxidative-stress-associated renal injury in endotoxemic rats : Involvement of nitric oxide and proinflammatory cytokines

This study aimed to investigate the effect of sesame oil on oxidative stress-associated renal injury induced by lipopolysaccharide in rats. The effects of sesame oil on renal injury, oxidative stress, hydroxyl radical, superoxide anion, nitric oxide, and proinflammatory cytokines were assessed after a lipopolysaccharide challenge. Sesame oil attenuated lipopolysaccharide-induced renal injury, decreased lipid peroxidation, increased the activities of superoxide dismutase, catalase, and glutathione peroxidase, reduced hydroxyl radical generation and nitric oxide production, and had no effect on superoxide anion generation in lipopolysaccharide-challenged rats. In addition, sesame oil significantly decreased tumor necrosis factor-α and interleukin 1β production 1 and 6 h, respectively, after lipopolysaccharide administration in mice. Thus, sesame oil attenuates oxidative stress-associated renal injury via reduction of the production of nitric oxide and the generation of proinflammatory cytokines in endotoxemic rats.

Attenuation of endotoxin-induced oxidative stress and multiple organ injury by 3,4-methylenedioxyphenol in rats

ABSTRACT Endotoxin is a potent inducer of lipid peroxidation (LPO), which is associated with the development of endotoxemia. 3,4-Methylenedioxyphenol (sesamol) is one of the sesame oil lignans with a high anti-LPO effect. Whether sesamol can attenuate endotoxin-induced LPO and multiple organ injury is unknown. After a dose response for sesamol in endotoxin-challenged rats was established, experiments were conducted to assess its effects on hydroxyl radical, peroxynitrite, and superoxide anion counts, activities of superoxide dismutase, catalase, and glutathione peroxidase, as well as the production of nitric oxide (NO) and the expression of inducible NO synthase. In addition, the effects of sesamol on endotoxin-induced hepatic and renal injuries were assessed. Sesamol (a) dose dependently reduced serum LPO inendotoxin-challenged rats, (b) decreased hydroxyl radical and peroxynitrite, but not superoxide anion counts, (c)increased the activities of superoxide dismutase, catalase, and glutathione peroxidase in endotoxin-treated rats, (d)reduced NO production and inducible NO synthase expression, and (e) attenuated hepatic and renal injuries induced by endotoxin in rats. We concluded that sesamol might protect against organ injury by decreasing NO-associated LPO in endotoxemic rats.

The effect of sesamol on systemic oxidative stress and hepatic dysfunction in acutely iron-intoxicated mice.

This study investigated the effect of sesamol (3,4-methylenedioxyphenol) on systemic oxidative stress and hepatic function in acutely iron-intoxicated mice. Sesamol reduced the levels of lipid peroxidation, hydroxyl radical, iron production and superoxide anion generation, and xanthine oxidase activity in iron-intoxicated mice. In addition, sesamol decreased the serum levels of aspartate aminotransferase and alanine aminotransferase, and ameliorated iron-intoxication-induced histological changes in the liver. In summary, sesamol might attenuate systemic oxidative stress by reducing xanthine oxidase and improving hepatic function in iron-intoxicated mice.

Effects of sesame oil on oxidative stress and hepatic injury after cecal ligation and puncture in rats.

Oxidative stress is known to be involved in the development of organ failure and death in sepsis. Sesame oil attenuates oxidative stress induced by endotoxin; however, whether sesame oil is still effective in rats with sepsis has never been investigated. The aim of the present study was to determine the effect of sesame oil on oxidative stress-associated hepatic injury in cecal ligation and puncture-induced rats with sepsis. We examined the effect of sesame oil (4 mL/kg daily for 1 week) on lipid peroxidation, hydroxyl radical, superoxide anion, and nitrite levels in rats with sepsis. In addition, hepatic injury was also assessed by blood biochemistry. Sesame oil significantly decreased lipid peroxidation and serum nitrite levels, but affected neither superoxide anion nor hydroxyl radical in cecal ligation and puncture-treated rats. Furthermore, sesame oil significantly attenuated cecal ligation and puncture-induced hepatic injury in rats. Nevertheless, oxidative stress and hepatic injury were not affected by corn oil or mineral oil in rats with sepsis. Thus, attenuation of oxidative stress and hepatic injury may be associated with inhibition of nitric oxide in sesame oil-associated protection in rats with sepsis.

Abamectin effects on aspartate aminotransferase and nitric oxide in rats

Abamectin is widely used as an insecticide and an anthelmintic. A previous report indicated that abamectin was used to commit suicide and led to death in Taiwan. This investigation focused on the toxicological effects of abamectin on serum aspartate aminotransferase (AST) and nitrate/nitrite (NO) levels in rats. After rats were gavaged with abamectin ranging from 1 to 20 mg/kg/body weight, AST and NO levels were examined within 12 h. AST and NO levels were elevated in abamectin-dosed rats in a dose-dependent manner. The least increase of AST corresponded to the highest enhancement of NO release at 6 h. A negative correlation coefficient (r=-0.55) between AST and NO was found. Both NG-nitro-L-arginine-methyl ester and aminoguanidine, inhibitors of nitric oxide synthase, increased the AST level induced by abamectin. These findings suggest that NO may be involved in the alteration of AST release induced by abamectin in rats.

Effects of sesame oil on oxidative stress after the onset of sepsis in rats.

The aim of this study was to investigate effects of sesame oil on oxidative stress after the onset of sepsis in rats. Effects of sesame oil on lipid peroxidation, superoxide anion, superoxide dismutase, catalase, glutathione, and nitrite after the onset of endotoxin intoxication were determined. To further examine the protective effect of sesame oil on sepsis, a mortality study was also conduced in cecal ligation and puncture-induced sepsis in rats. Sesame oil was given orally 6 h after endotoxin administration and cecal ligation and puncture, and parameters were then measured in another 6 h. Data demonstrated that a single dose of sesame oil reduced lipid peroxidation 6 h after endotoxin intoxication. Superoxide anion counts were decreased, glutathione levels were increased, and activities of superoxide dismutase and catalase, as well as nitrite levels, were not altered in lipopolysaccharide plus sesame oil-treated groups compared with lipopolysaccharide-treated groups. Furthermore, sesame oil given 6 h after cecal ligation and puncture significantly increased survival rate. Thus, we suggested that sesame oil could be used as a potent antioxidant to reduce oxidative stress after the onset of sepsis in rats.

Sesame oil attenuates Cisplatin-induced hepatic and renal injuries by inhibiting nitric oxide-associated lipid peroxidation in mice.

Although cisplatin (cis-diamminedichloroplatinum) is an effective drug for the treatment of several solid tumors and has been used therapeutically for decades, several cisplatin-induced side effects have limited its therapeutic dosage in clinical studies. Our aim was to examine the effect of sesame oil on cisplatin-induced hepatic and renal injuries in mice (8-week-old female SPF C57BL/6) given subcutaneous cisplatin (0, 5, 10, or 20 mg/kg). Hepatic and renal functions, lipid peroxidation (LPO) levels, and reactive oxygen free radicals were evaluated 3 days after cisplatin administration, and tumor volumes were recorded 0, 3, 6, and 9 days after cisplatin administration. Sesame oil (i) potently attenuated cisplatin-associated hepatic and renal injuries; (ii) decreased cisplatin-initiated LPO as well as the production of hydroxyl radical, peroxynitrite, and nitrite in blood and tissue; and (iii) did not affect the antitumor capacity exerted by cisplatin in mice with melanoma. We suggest that sesame oil attenuates cisplatin-induced hepatic and renal damage by at least partially inhibiting nitric oxide-associated LPO in mice. Sesame oil might be a new approach for preventing cisplatin-induced multiple organ injury during the treatment of tumors.

Sesamol attenuates diclofenac-induced acute gastric mucosal injury via its cyclooxygenase-independent antioxidative effect in rats.

We examined the protective effects of sesamol against acute gastric mucosal damage induced in rats by nonsteroidal anti-inflammatory drug diclofenac (DLF). We also measured the ulcer index, nitrite, iNOS, lipid peroxidation, hydroxyl radical, superoxide anion, reduced glutathione levels, prostaglandin E2, mucus, and cyclooxygenase activity in the rat mucosa. Sesamol attenuated gastric ulcer, nitrite, and iNOS in DLF-treated stomachs. Sesamol reduced mucosal lipid peroxidation and hydroxyl radical levels; however, neither DLF nor sesamol affected mucosal superoxide anion production. In addition, sesamol significantly maintained the reduced mucosal glutathione levels in DLF-treated stomachs of rats. Sesamol did not affect mucosal mucus production, but it further decreased DLF-induced mucosal prostaglandin E2 generation and cyclooxygenase activity. Therefore, sesamol might protect gastric mucosa against DLF-induced injury by inhibiting hydroxyl radical-associated lipid peroxidation. In addition, the cyclooxygenase pathway may not be involved in sesamols gastric mucosal protection.

Sesame oil attenuates hepatic lipid peroxidation by inhibiting nitric oxide and superoxide anion generation in septic rats

BACKGROUND Sepsis is a major cause of mortality in the intensive care unit. Oxidative stress plays an important role in the pathogenesis of organ failure during sepsis. Sesame oil decreases circulating oxygen free radicals in septic rats; however, its effect on hepatic oxidative status is unknown. The authors examined the effect of sesame oil on hepatic lipid peroxidation in septic rats. METHODS Hepatic injury was induced using cecal ligation and puncture (CLP). Rats were divided into 4 groups: sham, rats given a sham operation without CLP; SO, rats given sesame oil alone; CLP, rats given saline and then CLP; and CS, rats given sesame oil and then CLP. All rats were first given a 1-week daily oral supplement of sesame oil or saline (4 mL/kg/d) and then CLP or a sham operation. The authors assessed hepatic oxidative stress by determining hepatic lipid peroxidation, hydroxyl radical, superoxide anion, and nitric oxide levels 12 hours after CLP. They also assessed xanthine oxidase activity and nitric oxide synthase expression. RESULTS Hepatic lipid peroxidation (P < .0001), hydroxyl radical (P < .05), superoxide anion (P < .05), and nitrite (P < .05) levels were significantly lower in sesame oil-treated septic rats. Furthermore, sesame oil significantly reduced xanthine oxidase activity (P < .01) and inducible nitric oxide synthase expression (P < .005) in septic rats. CONCLUSIONS Sesame oil might attenuate hepatic lipid peroxidation by inhibiting superoxide anion and nitric oxide, at least partially, in experimental septic rats.